[appleburger]

a lot of you may have seen this before, but i just started really thinking about it. and before you go making uninformed comments, read the sites FAQ.

my thoughts are, mount it in the trunk and make a duct to channel air to it. the idea sounds good to me the way the site lays it out, but i'd be afraid of hitting my turbo on something or someone i know stealing it, thats why i'd want it in the trunk. apparently turbo lag isn't an issue with a kit like this because of the turbo and plumbing sizing, but it would be even less on a mid engine car. no intercooler needed because of the significantly lower temps, so you could save a TON of space in the engine bay. wouldn't be something guys who are already turbo would want to do, but maybe for the n/a guys like me. just a thought.

 

[TomsMR2]

the act of compressing air creates heat... you'd still need to run an intercooler.

 

[Critchie]

^^^^^
indeed. plus regardless of what they say there would be more lag, its just common sense. it would also cost you less to just buy a used ct26 and turbo manifold.

 

[lDeeZ lNuTz]

you're going to want the turbo to be somewhat hot or else it'll reduce exhaust speed. air travels faster when its hot and the turbo doesn't spool at it's max efficiency until it gets real hot.

 

[billwot]

...read the sites FAQ.

What "sites FAQ"?

bill

 

[darknight]

www.mr2oc.com/showthread.php?t=79951&highlight=trunk+mounted+turbo

here you go, hope this helps some. ive thought about this on my mk1, but i love the stockness of her, so i ditched it. oh yeah, read up on how oil must be fed. these guys used a electric pump to solve that problem. good luck, btw, i think that there's a mk1 in the link above that has it done w/ pictures.

 

[monkey nutz]

this might be an idea for guys who want to run 2 turbos. There is barely any room in the engine bay, but having a turbo underneath the car might work.

 

[appleburger]

What "sites FAQ"?

bill

____, my bad.

http://www.ststurbo.com/acura___honda

and as far as heat making the air move faster... thats not true. heat does not equal velocity, it equals volume.

and as for needing an intercooler...the turbo is out of the engine bay, getting much cooler air passing over it and the air going into it isn't quite as hot.

the lag would be noticeable, but they size the turbos much differently than you would for a conventional setup that makes up for any lag. and i don't see how it would create much more lag in a mid engine car than running a normal turbo and intercooler. if you mounted the turbo in your trunk, you wouldn't have much more piping that running i/c piping.

i don't think i'd ever do this to my car, but the site got me to thinking and it doesn't seem like a bad idea.

 

[lDeeZ lNuTz]

wow 1/8th mile at 95mph....that's damn impressive.

 

[billwot]

Thank you for posting it. I read it. Its silly! Probably to be expected at a Honduh site.

The farther the turbine is from the engine, the lower the energy will be to spin the turbo. The exhaust gasses lose both thermal energy and kinetic energy as they travel away from the engine.

Moving the compressor farther from the engine increases accumulator effect (lag) , increases frictional losses, and lowers charge air velocity.

As far as their concern about underhood temps, at highway speeds, even at full boost, MR2 3sgte engine compartment temps will not exceed 25-30F above ambient. That means on an 85F day, engine compartment temps will run ~110-120 during hard driving. I think everything under the hood IS designed to tolerate that.

There are hundreds of 3sgte MR2s that are 12-14 years old with 150-250K on the clock still performing very reliably. That red hot turbo doesn't seem to have done them any damage.

As a generalization, the shorter the distance on both sides of the turbo to the engine, the better the performance will be.

bill

 

[aspera]

As a generalization, the shorter the distance on both sides of the turbo to the engine, the better the performance will be.

bill

I know this is an old thread, but maybe you've all seen the Acura NSX with the remote mounted turbo by now. The guy squeezed one in between the rear carbon diffuser and the trunk floor. :thumbup

While I agree with the generalization, I have to point out that cramming a turbo right next to the engine makes for some sharp turns in the exhaust manifold and uneven header pipe lengths. This is a typical OEM trade-off of top end efficiency for better throttle response.

If you really think about the extra volume of exhaust pipe that needs to be filled in a remote mounted turbo on the Mk2, then you are talking about a few feet of small diameter tubing. That volume literally takes fractions of a second to fill.

Of course you lose heat energy, but you might only lose a few hundred degrees. The bearings in the turbo stay cooler and you don't need a turbo timer.

The most important thing to remember about remote mounted turbos are the other 3 pipes. Trunk mounted intercoolers are widely accepted in the MR2 world. Since the turbo is now mounted IN or UNDER the trunk, that takes care of that pipe.

The last two pipes are the key. The intake pipe can be a perfectly straight short pipe with a huge conical air filter. Ideal. The tailpipe can be the same. Ideal again. On cars and trucks with an engine mounted in the front, a muffler might not be needed. On a race car, you might not even bolt anything to the turbine housing.

Think about how those last two pipes would effect turbo lag. :thumbup

Now on a car like the MR2 turbo, it doesn't make much sense to reinvent the wheel. But if you are going to build an MR2 with a V6...